Locking key for shafts



Feb. 14, 1950 7H. P. STEVENS 2,497,634

LOCKING KEY FOR SHAFTS Filed Jan. 29, 1947 Patented Feb. 14, 1950 UNITED STATES PATENT OFFICE LOCKING KEY FOR "SI-IAFTS Harry P. Stevens, Oyster Bay, N. Y.

Application January 29, 1947, Serial No. 724,941

13 Claims, 1

The present invention relates to new and use improvements in locking keys for shafts and the like.

The fastening of gears, pulleys, etc. to shafts required some means of fastening them together and the most common means in use for this purpose has been flat or square keys all sides being parallel to be fitted into keyways of like proportion in the shaft and the element to be related thereto. In the usual practice, it is customary to out half the keyway in the shaft and the other half in the gear or other element to be fixed thereon. The keys are fitted so that when in operative position they would closely fit the outline of the ways. In some cases, keys are slightly tapered on the top to fit a corresponding taper in the ways and jammed in position at top and bottom only when operatively disposed. ZHowever, while it has been relatively easy to position these keys since that'could be achieved from one side of the element to be fixed on the shaft, it has been exceedingly difiicult to release the .key since the opposite end can seldom be reached to force the key out requiring special equipment and considerable time to achieve withdrawal.

It is an object of this invention to provide a simple form of shaft lock in the form of key pieces which can be operatively disposed in position from one side of the element to be fixed on the shaft and can be quickly and easily released or unlocked from the same side in an equally simple and rapid manner thus reducing the time and labor previously involved in disassembly.

Further and more specific objects, features, and advantages will more clearly appear from a consideration of the specification hereinafter set forth especially when taken in connection with the accompanying drawings which illustrate a present preferred form which the invention may assume and which form part of the specification.

In brief and general terms the invention includes a pair of key pieces which when assembled in the keyways have the same cross sectional outline as the ways and fill the same. The two key pieces have abutting faces and these faces are sloped both with respect to longitudinal as well as the transverse vertical planes through the pieces. Because of this double slope to the wedging faces, the two pieces can be inserted in a standard parallel sided keyway and secure a firm even wedging action on all sides and in addition permit easy removal from the same side as the insertion with no hand fitting required. Also because of this double slope the force exerted on the 2 pulley or other element by the shaft through the key pieces will tend to force the key pieces more firmly in position than otherwise would be the case.

The present preferred form of the invention is shown in the drawings of which,

Fig. 1 is an end elevation of a shaft with a pulley thereon and held thereto by the improved key;

Fig. 2 is an exploded perspective view of the two key pieces;

Fig. 3 is a plan view of the key pieces partly positioned in operative relation; and,

Fig. 4 is a partial elevation of a key disposedfor rotation of the shaft in a direction opposite to that shown in Fig. 1.

.As shownin the drawings, the specific preferred form is adapted to be applied to a shaft 10 on which it is desired to fix an element such as a pulley or wheel I]. A keyway is cut into the shaft and pulley, half .of it being in the shaft and the other half in the pulley and preferably standard rectangular ways.

In this form of keyway there is adapted to be disposed a key comprising two key pieces l2 and I3 having rectangularly related top, bottom, end and outside walls. These pieces are adapted to be disposed closely together in the way and when thus operatively disposed their cross section is rectangular. They are provided with adjacent abutting faces [4 and I5, and it is in the formation of these faces that the essence of the in vention lies. These pieces are wedge shaped but instead of the wedge slope being with respect to one plane it is developed with respect to two planes and therefore the slope of the abutting faces is of a bi-planar character. In the form of the key-pieces shown in Fig. 2 these surfaces are shown to slope from left to right as they extend from front to the rear and from right to left as they extend from bottom to top. These pieces as shown in this figure are designed to operatively tie the parts together for a shaft rotating clock-wise as shown in Fig. 1 whereas they are designed, as shown in Fig. 4, for a shaft rotating in the opposite direction and in consequence the bi-planar slopes are the reverse of those just mentioned.

It will be noticed from a consideration of the arrows in these two figures that the force exerted by the drive shaft upon the key unit will be in each case somewhat perpendicular to the plane of the abutting faces and this thus-directed force will tend to increase the cooperation between the key pieces and the keyway in which they are disposed.

The ease with which this unit may be assembled and taken apart is evident. In Fig. l, to insert the pieces into operative position, the left-hand piece as shown is inserted to the proper position and, while being held by means of a threaded screw inserted in the aperture 16, the right-hand piece is inserted and hammered into place by a series of blows. To release the pieces it is merely necessary to hold the ring-hand piece by a threaded screw inserted into the aperture H, and tap the left-hand piece with a series of light blows to move it forward slightly whereupon the abutting faces are moved apart and the right-hand piece can be removed and then the other one. In the form shown in Fig. 4 this action is of course reversed. The point to notice however, with re spect to each form, is that the pieces can be inserted and removed from the same side of the element being fixed on the shaft which has not hitherto been achieved without much more complicated means and taking more time and labor.

While the invention has been described in detail and with respect to present preferred forms which it may assume, it is not to be limited to such details and forms since many changes and modifications may be made in the invention without departing from the spirit and scope of the in vention in its broadest aspects. Hence, it is desired to cover any and all forms and modifications which may be made in the invention which may come within the language or scope of any one or more of the appended claims.

I claim:

1. A keyed assembly comprising a shaft and an element thereon formed with registering rectangular cross section, parallel wall recesses forming a keyway and a two-piece key means substantially conforming in cross section to the keyway when operatively disposed therein, said combined key pieces having forwardly and rearwardly disposed plane surfaces substantially coextensive with the forward and rearward side Walls of the keyway and said key pieceshaving 4 abutting plane surfaces sloped to provide for both longitudinal and vertical tapering of the key pieces and said key pieces being mated in reversely tapered relation.

2. A keyed assembly comprising a shaft and an element thereon formed with registering rectangular cross section, parallel wall recesses forming a keyway and a two-piece key means substantially conforming in cross section to the keyway when operatively disposed therein, said combined key pieces having forwardly and rearwardly disposed plane surfaces substantially coextensive with the forward and rearward side walls of the keyway and said key pieces havin abutting plane surfaces sloped to provide for both longitudinal and vertical tapering of the key pieces and said key pieces being mated in reversely tapered relation and provided with threaded apertures in their end portions to facilitate withdrawal of the key.

3. A keying means adapted to lock a shaft to an element thereon which comprises two key pieces formed to be substantially rectangular in cross section when disposed together, said pieces having plane, forward and rearwardl disposed outer side surfaces permitting vertical displacement Within a key slot and having abutting flat faces which slope to provide a bi-planar tapering of the pieces and said pieces being provided with threaded apertures in their end portions to facilitate dismantling.

HARRY P. STEVENS.

REFERENGES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,277,331 Kysor Mar. 24, 1942 FOREIGN PATENTS Number Country Date 17,780 Great Britain Aug. 25, 1908 

